The sum of $3$ consecutive odd numbers is $51$. What is the second number in this sequence?
Explanation: Call the first number in the sequence $x$. The next odd number in the sequence is $x + 2$ The sum of the $3$ consecutive odd numbers is: $x+ (x + 2)+ (x + 4) = 51$ $3x + 6= 51$ $3x = 45$ $x = 15$ Since $x$ is the first number, $x + 2$ is the second odd number. Thus, the second number in the sequence is $17$.